Yellowjackets (including V. pensylvanica, V. germanica and V. vulgaris) and other members of the wasp family, Vespidae, are widely found across North America and are considered to be pests when they interact with humans. Schools, swimming pools, parks, picnic areas, and homes can all be negatively impacted by Vespidae, and many people can suffer from allergic reactions, some of which can be fatal. One of the more nuisance forms of Vespidae is the genus of Vespula, including various species of yellowjackets. Since most yellowjacket colonies begin new nests each season, managing their populations can be a challenge. Most pest management techniques for Vespidae involve trapping of Vespidae as they forage, but often these techniques do not adequately address the pest issue.
The life cycle of most Vespidae nests begins in winter, when fertilized Vespidae queens go into hibernation. Queens may hibernate in covered natural locations such as tree stumps, hollow logs, the ground and also in man-made structures. In the spring, the queen will emerge, search for a new nest location, build a nest, and begin laying her eggs. After the initial eggs hatch into larvae, the queen feeds her young with scavenged meat, fish and other insects. As adults, these first offspring are sterile female workers that expand the nest, search for food and care for the queen and her young. After her first generation matures, the queen remains inside the nest laying eggs for the rest of the summer. The diet of most Vespidae including yellowjackets varies throughout the season and includes both fruit-based sugars and nectars as well as proteins including meat, fish and insects. At its height, a colony may contain 5,000 or more worker wasps.
In the fall, nests will contain larvae ready to become adult males and fertile females. These males and females will leave their colonies to mate. After mating, males die and the fertilized females go in search of hibernation locations. Worker wasps perish in winter, leaving the hibernating queen to begin anew in spring.
Most current trapping methods for Vespidae involve setting traps in perimeters surrounding areas and filling the traps with attractants of Vespidae. Controlling populations of Vespidae such as V. pensylvanica is difficult due to the size and location of the nests. However, the use of traps against these Vespidae is a common method of reducing their interactions with humans. Usually, these liquid-drowning or dehydration traps contain one or more chemical attractants. Frequently, this includes synthetic heptyl butyrate (HB), a commonly-used yellowjacket lure which is highly attractive to V. pensylvanica and other species of Vespidae including V. atripilosa, V. sulphurea, V. consobrina, V. acadica, V. squamosa, V. vidua, V. vulgaris, V. maculifrons, and V. germanica. Other butyric acid ester attractants related to heptyl butyrate which are also known to be attractants to similar Vespidae include butyl butyrate, hexyl butyrate, octyl butyrate and nonyl butyrate (EI-Sayed A M et al. 2009; McGovern et al. 1970). Isobutanol, 1-methyl-1-butanol and 2-methyl butanol are also known to be a attractants of other yellowjacket species (Landolt. 2016).
In some commercial traps, a combination of isobutanol, 1-methyl-butanol or 2-methyl-1-butanol or 2-ethyl-1-butanol and acetic acid are used together with heptyl butyrate to enhance the attraction to certain yellowjacket and wasp species including a hornet (Vespa crabro) and several paper wasps (Polistes spp.) (U.S. Pat. No. 6,083,498). It was found that while 2-methyl-1-butanol is similarly effective as isobutanol when used with acetic acid to attract various Vespidae, it has a more favorable vapor pressure than isobutanol (Landolt P. 2000; Landolt 2016). While these traps can effectively trap some Vespidae, the efficacy of the traps is largely dependent upon attractants to lure these Vespidae to them. As a result, the effectiveness of the traps is directly related to the effectiveness of the attractants.
Herein are described novel compositions of heptyl butyrate and other volatile attractants along with specific acids that are used in combination to create novel compositions of attractants which are more effective at attracting yellowjackets and other Vespidae than the volatile attractants on their own. Importantly, these enhanced combination of attractants are not attractive to honey bees or other beneficial insects.